Here it is side-by-side with a traditional watch mechanism:

There have been rumours that the Apple Watch might be upgradable, especially for the high-end Apple Watch Edition, to justify that £13,500/$17,000 price tag. But iFixit thinks that this is highly unlikely, given how difficult the internal chips are to remove.

The internal battery is a 205mAh, iFixit has found, compared to the iPhone 6's 1,810mAh. The smaller size of the Apple Watch's screen and its power-saving features mean it will require far less energy to run, however.